TW201519283A - Discharge lamp - Google Patents

Abstract

The purpose of the present invention is to form an electrode having high weld strength by means of solid-state welding. Specifically provided is a short-arc discharge lamp wherein a sealed space (50) is provided within a positive electrode (30). A heat-transfer member (M) is encapsulated in the sealed space (50). The positive electrode (30) comprises a body member (32) with a recess (50S) formed therein, a lid member (36) for covering the body member (32), and an annular intermediate member (40) interposed between the body member (32) and the lid member (36), and is formed through the solid-state welding of the body member (32), the intermediate member (40) and the lid member (36) by spark plasma sintering (SPS).

Description

Discharge lamp tube, electrode for discharge lamp tube and method for manufacturing the same

The present invention relates to a discharge lamp for use in an exposure apparatus or the like, and particularly relates to an electrode structure in which a heat transfer body is sealed in a sealed space formed inside an electrode.

Among the discharge lamps, an electrode in which a sealed space is formed inside the electrode and a metal having a cooling function is sealed is known (refer to Patent Document 1). Further, a heat transfer material made of a metal having a high thermal conductivity such as silver and a relatively low melting point is sealed inside the anode. When the temperature of the electrode rises due to the lighting of the lamp, the heat transfer body is melted and liquefied. Therefore, heat convection occurs in the sealed space, and heat at the tip end portion of the electrode is transported to the electrode support rod side on the opposite side.

When a sealed space is formed inside the electrode, the concave portion including the tip end portion of the electrode and the lid portion are formed first, and then the both are joined. The bonding method can perform solid phase bonding by plasma sintering or the like, and a bottomed cylindrical metal member having a concave portion therein is joined to a metal member as a lid to form an electrode. By solid phase bonding, an electrode can be formed without reducing thermal conductivity and electrode strength (see Patent Document 2).

[Advanced technical literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-006246

[Patent Document 2] Japanese Laid-Open Patent Publication No. 2011-249027

The heat transfer body that rises from the vicinity of the tip end portion of the electrode is extremely heated, and the joined portion is heated. Therefore, a strong joint is required. However, if the pressing pressure at the time of solid phase joining is enhanced, the main body member is easily deformed due to the formation of the internal space. If the deformation is large, cracks may occur in the inner surface of the confined space, causing damage to the electrode when the lamp is lit.

Therefore, it is necessary to constitute an electrode which does not deform in the vicinity of the joint portion at the time of solid phase joining and has high joint strength.

The discharge lamp of the present invention comprises: a discharge tube; and a pair of electrodes disposed in the discharge tube, wherein at least one of the electrodes comprises: a member formed with a recess (referred to herein as a body member); and a member covering the body member A member (referred to herein as a cover member); and an annular member (referred to herein as an intermediate member) interposed between the body member and the cover member. The electrode of at least one of the above is formed by joining the main body member, the intermediate member, and the cover member by solid phase. A heat transfer body is sealed in a sealed space formed inside the electrode by solid phase bonding.

The body member may be formed integrally with the electrode tip end surface and the electrode tip end portion, or may be formed by the joint electrode tip end portion. The concave portion may be formed in a tubular shape as long as it is formed as a space in which heat convection of the heat transfer body can be generated. For example, a cylindrical cross-sectional internal space is formed in a cylindrical main body member. The cover member is engaged, for example, with an electrode support rod.

In the present invention, by providing the annular intermediate member, the stress can be uniformly applied when the solid phase is joined to the non-annular cover portion. On the joint surface as a whole. Therefore, deformation of the main body member can be suppressed. Further, when the lamp is turned on, the heat transfer body directly reaches the cover member, and the heat transfer efficiency of the intermediate member is not lowered.

The size of the hole of the intermediate member can be arbitrarily set, and can be appropriately set within a range in which the deformation of the main body member is suppressed and the heat transfer effect of the heat transfer body is achieved. For example, the same size can be set according to the size (diameter) of the internal space of the main body member. The outer diameter and the inner diameter of the intermediate member may or may not coincide with the outer diameter and the inner diameter of the main body member.

When the intermediate member is used to improve the effect of the solid phase joining, the intermediate member is not too thick, and the radial width of the intermediate member and the thickness of the intermediate member are preferably balanced. For example, the radial width of the intermediate member can be set to be twice or less the thickness of the intermediate member.

In view of the fact that the intermediate member absorbs the pressing force at the time of solid phase joining, it is preferable to form the intermediate member with a material having a higher ductility than at least one of the main body member and the lid member. For example, the intermediate member is made of a metal of any one of tungsten, molybdenum, niobium, and tantalum, or an alloy containing any of the above as a main component.

As a structure in which the stress in the direction of the electrode axis is released to the outside of the electrode to suppress deformation, the area of the joint surface of the intermediate member can be made smaller than the cross-sectional area of the body member. For example, the outer diameter of the intermediate member can be made smaller than the outer diameter of the main body member. In this case, the inner diameter of the intermediate member may be made to coincide with the inner diameter of the body member, or may be a smaller inner diameter.

It is also possible to make the inner diameter of the intermediate member larger than the inner diameter of the main body member. In this case, the outer diameter of the intermediate member may be made to coincide with the outer diameter of the body member, or may be a larger outer diameter.

Considering the solid phase bonding between the cover member and the intermediate member In this case, the outer diameter of the cover member can be made smaller than the outer diameter of the main body member. For example, the outer diameter of the cover member can be made to coincide with the outer diameter of the intermediate member. On the other hand, as the structure which can obtain the same effect as the above-described structure, the outer diameter of the joint surface of the main body member may be made smaller than the outer diameter of the intermediate member.

Regarding the cover member, it is considered that the intermediate member is opposed to the entire electrode When the relative position of the axial direction is close to the bottom surface side of the internal space, the cover recessed portion may be provided on the side of the sealed space.

Another electrode for a discharge lamp tube according to another aspect of the invention includes: a main The body member is formed with a recess; the cover member covers the body member; and the annular intermediate member is interposed between the body member and the cover member. The electrode for a discharge lamp is formed by solid-phase bonding of a main body member, an intermediate member, and a cover member, and a heat transfer body is sealed in a sealed space formed inside the electrode by solid phase bonding.

A method of manufacturing an electrode for a discharge lamp according to another aspect of the present invention, The method includes: forming a main body member having a recess, a cover member covering the recess of the main body member, and an intermediate member forming an annular shape; placing a heat transfer body on the concave portion of the main body member; interposing the intermediate member into the main body member and the cover member The body member, the intermediate member, and the cover member are bonded to each other to form an electrode.

According to the invention, it is possible to form an electrode having a high bonding strength by solid phase bonding.

10‧‧‧Discharge lamp

12‧‧‧Discharge tube

13A, 13B‧‧‧ sealed tube

15A, 15B‧‧‧ guide bars

16A, 16B‧‧‧metal foil

17A, 17B‧‧‧electrode support rod

19A, 19B‧‧‧ metal cover

20‧‧‧ cathode

30, 130, 230, 330, 430, 530‧ ‧ anode

30S‧‧‧ front end face of electrode

32, 132, 232, 332, 432, 532‧‧ ‧ body components

32S‧‧‧ end face

34‧‧‧ front end

36, 136, 236, 336, 436, 536 ‧ ‧ cover members

36S, 236T‧‧‧ end face

40, 140, 240, 340, 440, 540, 550‧‧‧ intermediate components

40S‧‧‧ end face

50, 150, 250, 350, 450‧‧‧ confined spaces

50B‧‧‧ bottom

50S, 237‧‧ ‧ recess

533‧‧‧Wedge

B‧‧‧thickness

D1, d2‧‧‧ inside diameter

D1, D2, D3‧‧‧ OD

DS‧‧‧discharge space

E‧‧‧electrode shaft

M‧‧‧ heat transfer body

T‧‧‧diameter width

S1, S2‧‧‧ sectional area

Fig. 1 is a plan view schematically showing a short arc type discharge lamp of the first embodiment.

Fig. 2 is a schematic cross-sectional view of the anode.

Fig. 3 is a cross-sectional view taken along the vertical direction of the electrode axis of the main body member and the intermediate member.

Fig. 4 is a cross-sectional view showing the joint portion of Fig. 2 in an enlarged manner.

Fig. 5 is a schematic cross-sectional view showing an anode of a discharge lamp of a second embodiment.

Fig. 6 is a schematic cross-sectional view showing an anode of a third embodiment.

Fig. 7 is a cross-sectional view showing the intermediate member and the main body member of the third embodiment.

Fig. 8 is a cross-sectional view showing the joint portion of Fig. 6 in an enlarged manner.

Fig. 9 is a cross-sectional view showing a joint portion of the fourth embodiment.

Fig. 10 is a cross-sectional view showing the anode of the fifth embodiment.

Figure 11 is a cross-sectional view showing the anode of the sixth embodiment.

Fig. 12 is a graph showing the relationship between the ratio of the joint area (the end surface area of the intermediate member) to the cross-sectional area of the end surface of the main body member and the amount of deformation of the main body member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a plan view schematically showing a short arc type discharge lamp of the first embodiment.

The short-arc discharge lamp tube 10 is a discharge lamp tube that can be used as a light source or the like for forming an exposure device (not shown) for patterning, and includes a discharge tube (light-emitting tube) 12 made of transparent quartz glass. In the discharge tube 12, the cathode 20 and the anode 30 are arranged to face each other with a predetermined interval therebetween.

On both sides of the discharge tube 12, sealed tubes 13A, 13B made of quartz glass are opposed to each other and integrally provided with the discharge tube 12, and both ends of the seal tubes 13A, 13B are plugged by the metal covers 19A, 19B. The discharge lamp 10 is disposed along the vertical direction so that The anode 30 is located on the upper side and the cathode 20 is located on the lower side.

The inside of the sealed tubes 13A, 13B is provided with a cathode supporting metal 20. Conductive electrode support rods 17A and 17B of the anode 30 are connected to the conductive rods 15A and 15B via metal rings (not shown) and metal foils 16A and 16B such as molybdenum. The sealed tubes 13A and 13B are welded to glass tubes (not shown) provided in the sealed tubes 13A and 13B, thereby generating a discharge space DS in which mercury and an inert gas are sealed.

The guide bars 15A, 15B are connected to an external power supply unit (not shown), Voltage is applied between the cathode 20 and the anode 30 through the guide bars 15A, 15B, the metal foils 16A, 16B, and the electrode support bars 17A, 17B. When electric power is supplied to the discharge lamp tube 10, an arc discharge occurs between the electrodes, and a bright line (ultraviolet light) is emitted from the mercury.

Fig. 2 is a schematic cross-sectional view of the anode.

The anode 30 is a cylindrical metal member (hereinafter referred to as a main body member) 32, a cylindrical metal member (hereinafter referred to as a cover member) 36 joined to the electrode support rod 17B, and a ring interposed between the main body member 32 and the cover member 36. A metal member (hereinafter referred to as an intermediate member) 40 is formed.

The main body member 32 is a thick-bottomed cylindrical member integrally connected to the truncated cone-shaped distal end portion 34 (the distal end portion 34 has the electrode distal end surface 30S along the vertical direction of the electrode axis (lamp axis) E). Further, a recess 50S is formed inside. The main body member 32 is made of a metal formed of pure tungsten (W) or an alloy mainly composed of tungsten.

Similarly to the main body member 32, the cover member 36 is made of tungsten or a metal such as tantalum or molybdenum, and covers the main body member 32 through the intermediate member 40 to seal the concave portion 50S of the main body member 32. Thereby, the sealed space 50 is formed in the inside of the anode. Any one of the main body member 32, the intermediate member 40, and the cover member 36 is coaxially disposed. The width of the main body member 32 and the lid member 36 in the radial direction in the direction of the electrode axis, that is, the material thickness, is constant in the vicinity of the joint portion.

The annular intermediate member 40 is made of tungsten, molybdenum, niobium, tantalum and niobium. The formed metal is composed of an alloy containing tungsten, molybdenum, niobium, tantalum, and niobium as a main component. The intermediate member 40 is extremely thinner than the cover member 36 and the body member 32. The intermediate member 40 is more ductile than the body member 32, the cover member 36, or either.

The sealed space 50 is enclosed by the main body member 32 and the intermediate member 40. The cover member 36 is composed of a metal having a lower melting point (silver or the like) or a heat transfer body M containing these metals as a main component. In the lamp lighting, since the electrode tip end portion 34 is heated, the heat transfer body M is melted. The melting points of the main body member 32, the lid member 36, and the intermediate member 40 are higher than the melting point of the heat transfer body M, and are also higher than the temperature (about 1800 ° C) in the vicinity of the bottom surface 50B of the internal space in the lamp lighting.

The molten heat transfer body M convects in the sealed space 50 to make the electrode front end The heat of the portion 34 is sent to the side of the cover member 36 along the electrode axis E. Thereby, the anode 30 is cooled in the lamp lighting.

The anode 30 in which such a sealed space 50 is formed is followed by Formed by solid phase bonding in the form of spark plasma sintering (SPS sintering). The metal members constituting the main body member 32, the lid member 36, and the intermediate member 40 are formed by sintering and solidifying the metal powder. Then, after the solidified heat transfer body M is placed in the recess 50S of the main body member 32, the device for discharge plasma sintering (SPS) is used to adjust the superheat, pressurization, pressurization time, and the like while joining the above three metal members. .

Figure 3 is perpendicular to the electrode axis of the body member and the intermediate member. A sectional view of the direction. Fig. 4 is a cross-sectional view showing the joint portion of Fig. 2 in an enlarged manner. Next, the shape of the intermediate member will be described using Figs. 2 to 4.

As described above, the intermediate member 40 is an annular sheet having a high ductility. Here, the thickness b is set to be 1/2 or less of the width (material thickness) t in the radial direction. If the thickness b exceeds 1/2 of the width t, the intermediate member 40 is largely deformed at the time of solid phase engagement, so that the cover portion 36 is offset from the axis of the body member 32.

The intermediate member 40 has a shape that is only connected to the end surface 36S of the lid member 36 and a part of the end surface 32S of the body member 32, and is not connected to the entire end surface 36S and the end surface 32S. The cross-sectional area S2 of the intermediate member 40 is smaller than the cross-sectional area S1 of the cylindrical portion of the main body member 32. In other words, the area of the end surface 40S which is the joint surface of the intermediate member 40 is smaller than the area of the end surface 32S which is the joint surface of the main body member 32.

The inner diameter d1 of the intermediate member 40 is equal to the inner diameter d2 of the main body member 32, but the outer diameter D2 of the intermediate member 40 may be smaller than the outer diameter D1 of the main body member 32. The outer diameter D3 of the cover member 36 is equal to the outer diameter D1 of the body member 32.

By providing such an intermediate member 40, the joint strength can be further improved. That is, the intermediate member 40 is annular, and the volume ratio (size) in the direction of the electrode axis is also the smallest at the portion of the intermediate member 40, so the intermediate member 40 functions as a cushioning material. Therefore, it is possible to prevent a strong stress from being applied to the main body member 32 from the side of the cover member 36 at the time of solid phase bonding.

In particular, since the intermediate member 40 has higher ductility than the other members, the intermediate member 40 is most compressively deformed along the electrode axis direction at the time of solid phase bonding. Therefore, the compressive stress on the main body member 32 at the time of solid phase joining is reduced, and the deformation of the main body member 32 is suppressed. This improves the main body member 32, the intermediate member 40, and the cover member 36. The joint strength of the joint portion prevents cracks from being generated from the joint portion due to heat transmitted from the heat transfer body M.

Since the intermediate member 40 is annular, the flow of the rising heat transfer body M The movement directly reaches the end face 36S of the cover member 36. Therefore, the configuration of the intermediate member 40 does not reduce the heat transfer efficiency.

On the other hand, the cross-sectional area of the intermediate member 40 is larger than that of the main member 32 The cross-sectional area is small, and only the inner side portion of the end surface of the main body member 32 is joined to the entire end surface 40S of the intermediate member 40. Therefore, the stress applied at the time of solid phase bonding is concentrated on a relatively small contact area, and the joint strength is further improved.

The outer diameter D2 of the intermediate member 40 is smaller than the outer diameter D1 of the main body member 32, The outer side of the end surface 32S of the main body member 32 is not connected to the intermediate member 40. Therefore, at the time of solid phase bonding, the stress in the radial direction can be released to the outer portion of the body member 32, and the electrode can be formed without deforming the shape of the body member 32.

Cross section of the cross-sectional area S2 of the intermediate member 40 with respect to the main body member 32 The ratio of the area S1 can be set in the range of 40 to 90%. If the ratio is smaller than 40%, the cross-sectional area of the joint portion is too small to strongly hold the main body member 32. If the ratio is larger than 90%, the stress is hard to be released to the outer portion of the main body member 32.

According to this embodiment, the anode 30 includes a body forming the recess 50S The member 32, the cover member 36 covering the body member, and the annular intermediate member 40 interposed between the body member and the cover member. The anode 30 is formed by solid-phase joining of the main body member 32, the intermediate member 40, and the cover member 36 by SPS.

In addition, the inner diameter of the intermediate member may be made larger than the inner portion of the main body member. The small diameter constitutes a structure in which the intermediate member protrudes toward the side of the sealed space.

Next, a discharge lamp of the second embodiment will be described with reference to Fig. 5. 2nd In the embodiment, carbon fiber is used as the heat transfer body. The other structure is the same as that of the first embodiment.

Fig. 5 is a schematic cross-sectional view showing an anode of a discharge lamp of a second embodiment.

The anode 130 is composed of a body member 132, an intermediate member 140, and a cover member 136. The heat transfer body M1 composed of a carbon fiber bundle is disposed in a sealed space. The heat transfer body M1 extends from the bottom surface of the sealed space 150 to the cover member 136.

Next, a discharge lamp of a third embodiment will be described using Figs. 6 to 8. In the third embodiment, the cover member is provided with a recess, and the intermediate member is located outside the end surface of the body member. The other configuration is substantially the same as that of the first embodiment.

Fig. 6 is a schematic cross-sectional view showing an anode of a third embodiment. Fig. 7 is a cross-sectional view showing the intermediate member and the main body member of the third embodiment. Fig. 8 is a cross-sectional view showing the joint portion of Fig. 6 in an enlarged manner.

The anode 230 is composed of a main body member 232, an intermediate member 240, and a cover member 236, and the heat transfer body M is sealed in the sealed space 250. The sealed space side end surface 236T of the cover member 236 is formed with a trapezoidal recessed portion 237 that is formed around the center portion and that is spread around the center. With such a shape, the axial direction position of the intermediate member 240 in the entire length of the anode is close to the bottom surface side of the internal space. In other words, the main body member 232 is shortened in the axial direction without changing the volume of the internal space, and the deformation of the main body member 232 is prevented by the pressing force at the time of solid phase joining. Further, the concave portion 237 can also have a cylindrical shape.

As shown in FIGS. 7 and 8, the cross-sectional area S2 of the intermediate member 240 is smaller than the cross-sectional area S1 of the main body member 233. The outer diameter D2 of the intermediate member 240 is equal to the outer diameter D1 of the main body member 232, and the inner diameter d2 of the intermediate member 240 is larger than that of the main body member 232 The inner diameter d1 is large. The outer diameter D3 of the cover member 236 is equal to the outer diameter D1 of the body member 232.

The end face of the body member 232 is joined by the intermediate member 240 like this In the outer portion, when the SPS is solid-phase bonded, the current mostly flows on the electrode side surface side due to the skin effect, so that the joint strength can be improved. In particular, the joint strength in the vicinity of the inner peripheral surface of the intermediate member 240 is improved.

The inner circumferential surface of the intermediate member 240 is more than the inner circumferential surface of the main body member 232 Located on the side of the electrode side, the joint portion is formed in a concave shape. Thereby, the flow of the heat transfer body M does not directly affect the intermediate member 240, and the heating of the joint portion can be suppressed. Further, the outer diameter of the intermediate member may be made larger than the outer diameter of the main body member, and the intermediate member may protrude from the side surface of the electrode.

Next, a discharge lamp of the fourth embodiment will be described using FIG. In the fourth embodiment, the intermediate member is disposed at a central portion of the end surface of the body member. The other structure is substantially the same as that of the first embodiment.

Fig. 9 is a cross-sectional view showing a joint portion of the fourth embodiment.

The anode 330 is composed of a main body member 332, an intermediate member 340, and a cover member 336, and a heat transfer body (not shown) is sealed in the sealed space 350. The outer diameter D2 of the intermediate member 340 is smaller than the outer diameter D1 of the main body member 332. The inner diameter d2 of the intermediate member 340 is larger than the inner diameter d1 of the main body member 332. The outer diameter D3 of the cover member 336 is equal to the outer diameter D1 of the body member 332.

Next, a fifth embodiment will be described using FIG. In the fifth embodiment, the outer diameter of the main body member is larger than the outer diameter of the intermediate member. The other structure is substantially the same as that of the first embodiment.

Fig. 10 is a cross-sectional view showing the anode of the fifth embodiment.

The anode 430 is composed of a main body member 432, an intermediate member 440, and a cover member In the case of 436, the heat transfer body M is sealed in the sealed space 350. The outer diameter D2 of the intermediate member 440 and the outer diameter D3 of the cover member 436 are smaller than the outer diameter D1 of the main body member 432.

The side surface side of the electrode in the joint surface of the main body member is thus The non-contact portion can obtain the same effects as those of the first embodiment. Further, since the outer diameter of the cover member is equal to the outer diameter of the intermediate member, the electrode side surface side portion of the cover member is joined to the intermediate member, and the joint strength between the cover member and the intermediate member is improved.

Next, the sixth embodiment will be described using Fig. 11 . Sixth embodiment In the state, unlike the first to fourth embodiments, the outer diameter of the joint surface of the main body member is smaller than the outer diameter of the intermediate member.

Figure 11 is a cross-sectional view showing the anode of the sixth embodiment.

The anode 530 is composed of a main body member 532, an intermediate member 540, and a cover member. According to 536, the heat transfer body M is enclosed in the sealed space 550. A wedge 533 is formed on a side surface of the body member 532 near the joint portion. Therefore, the outer diameter of the joint surface of the main body member 532 is shorter than the outer diameter of the intermediate member 540. In the end surface of the intermediate member 540, the electrode side end side end portion is not engaged with the body member 532. The outer diameter of the cover member 536 is equal to the outer diameter of the intermediate member 540.

With this configuration, the stress at the time of solid phase bonding can be made to the main structure Released near the side of the piece. The deformation of the main body member 532 can be prevented.

[Embodiment 1] A discharge lamp tube according to Embodiment 1 of the present invention will be described below.

The anode of the discharge lamp is composed of a main body member formed of pure tungsten, a cover member, an alloy containing tungsten or rhenium, or an intermediate member formed of molybdenum/ruthenium. The discharge lamp tube is formed by solid-phase joining the main body member, the cover member, and the intermediate member prepared separately by SPS. Here, the outer diameter, the inner diameter of the main body member, the outer diameter of the intermediate member, and the inner diameter are set as follows: 35 body member inner diameter: twenty two

Outer member outer diameter: 35 intermediate member inner diameter: twenty four

A tensile test was performed on the manufactured anode. In addition, a conventional discharge lamp tube in which an intermediate member is not provided is used as a comparative example. The results are shown in Table 1 below.

Tensile strength indicates the strength in the direction in which the electrode is torn along the electrode axis. Check for cracks near the joint after 750 hours of lighting. As shown in Table 1, the joint strength can be improved by providing the intermediate member.

[Embodiment 2] Next, a discharge lamp tube according to Embodiment 2 of the present invention will be described.

The anode of the discharge lamp of Example 2 is composed of a main body member made of pure tungsten, a cover member, an alloy containing tungsten, niobium, or an intermediate member formed of molybdenum/ruthenium. The anode of the discharge lamp is formed by solid-phase joining the main body member, the cover member, and the intermediate member prepared separately by SPS. The anode of the second embodiment is of the first embodiment, and the outer diameter of the intermediate member is shorter than the outer diameter of the main body member. Here, the outer diameter, the inner diameter of the main body member, and the inner diameter of the intermediate member are set as follows: outer diameter of the main body member: 35 body member inner diameter: twenty two

Outer member outer diameter: 33 Intermediate member inner diameter: twenty two

Here, the anode is manufactured by performing solid phase bonding of SPS while changing the outer diameter of the intermediate member, and the amount of deformation of the body member is measured each time.

Figure 12 shows the joint area (intermediate member end face area) in a graph The relationship between the ratio of the cross-sectional area of the end surface of the main body member and the amount of deformation of the main body member. As shown in Fig. 12, the smaller the sectional area of the intermediate member, the smaller the amount of deformation of the main body member.

[Embodiment 3] Next, Embodiment 3 of the present invention will be described. Example 3 In the case where the position of the intermediate member is placed at the positions (inner side, outer side, and center) corresponding to the first, third, and fourth embodiments, the stress applied to the inner surface of the body member is calculated by a simulation program. The results are shown in Table 2 below. The model of the anode used for the calculation sets the outer diameter, inner diameter, outer diameter and inner diameter of the main member as follows:

Inside

Body member outer diameter: 35 body member inner diameter: twenty two

Outer member outer diameter: 33 Intermediate member inner diameter: twenty two

Outside

Body member outer diameter: 35 body member inner diameter: twenty two

Outer member outer diameter: 35 intermediate member inner diameter: twenty four

central

Body member outer diameter: 35 body member inner diameter: twenty two

Outer member outer diameter: 34 Intermediate member inner diameter: twenty three

In Table 2, the stress when the intermediate member is configured as in the third embodiment is indicated by 1. As is apparent from Table 2, when the intermediate member is disposed inside as in the third embodiment, the stress is reduced.

17B‧‧‧electrode support rod

30‧‧‧Anode

30S‧‧‧ front end face of electrode

32‧‧‧ body components

32S‧‧‧ end face

34‧‧‧ front end

36‧‧‧Cover components

36S‧‧‧ end face

40‧‧‧Intermediate components

50‧‧‧Confined space

50B‧‧‧ bottom

50S‧‧‧ recess

E‧‧‧electrode shaft

M‧‧‧ heat transfer body

Claims (13)

A discharge lamp tube comprising: a discharge tube; and a pair of electrodes disposed in the discharge tube, wherein at least one of the electrodes comprises: a body member formed with a recess; a cover member covering the body member; and an annular An intermediate member interposed between the main body member and the cover member, wherein at least one of the electrodes is formed by solid-phase bonding the main body member, the intermediate member and the cover member, and is formed on the electrode by solid phase bonding The internal sealed space is sealed with a heat transfer body. The discharge lamp of claim 1, wherein an area of the joint surface of the intermediate member is smaller than a cross-sectional area of the body member. A discharge lamp according to any one of claims 1 to 2, wherein an outer diameter of the intermediate member is smaller than an outer diameter of the main body member. A discharge lamp according to any one of claims 1 to 2, wherein an inner diameter of the intermediate member is larger than an inner diameter of the main body member. The discharge lamp of any one of claims 1 to 4, wherein the cover member has an outer diameter smaller than an outer diameter of the body member. The discharge lamp of claim 1, wherein an outer diameter of the joint surface of the main body member is smaller than an outer diameter of the intermediate member. The discharge lamp according to any one of claims 1 to 6, wherein the intermediate member has a radial direction width which is twice or less the thickness of the intermediate member. The discharge lamp according to any one of claims 1 to 7, wherein the cover member has a cover recess on the side of the sealed space. The discharge lamp of any one of claims 1 to 8, wherein the intermediate member is more ductile than at least one of the body member and the cover member. The discharge lamp according to any one of claims 1 to 9, wherein the intermediate member is a metal of any one of tungsten, molybdenum, niobium and tantalum, or an alloy mainly composed of any one of the above. Formed. A discharge lamp according to any one of claims 1 to 10, wherein a melting point of the intermediate member is higher than a temperature of a front end portion of the electrode in the lamp lighting. An electrode for a discharge lamp, comprising: a main body member formed with a concave portion; a cover member covering the main body member; and an annular intermediate member interposed between the main body member and the cover member, wherein the discharge lamp electrode is The main body member, the intermediate member, and the cover member are joined by solid phase bonding, and a heat transfer body is sealed in a sealed space formed inside the electrode by solid phase bonding. A method of manufacturing an electrode for a discharge lamp, comprising: forming a body member having a recess, a cover member covering a recess of the body member, and an annular intermediate member; placing a heat transfer body in the recess of the body member; A member is interposed between the body member and the cover member, and the body member, the intermediate member, and the cover member are solid-phase bonded to form an electrode.